Page 523 - Anatomy and Physiology of Farm Animals, 8th Edition

508 / Anatomy and Physiology of Farm Animals

Mammary Glands of Sheep of pairs may range from four to nine, and
and Goats
supernumerary teats are sometimes found
VetBooks.ir The udders of the ewe and the doe between normal teats. Sows average 2.5
more teats than the number of piglets in
(Fig. 29‐6) differ from that of the cow in their average litter. Glands that are under-
that each half of the udder has only one used dry up and do not develop again until
teat, one streak canal, one teat cistern, and the next pregnancy.
one gland cistern. One half of the ovine Inverted teats (concave nipples) and
and caprine udder resembles one quarter mastitis are two of the most common
of the bovine udder. The teat is sparsely conditions adversely affecting the mam-
covered with fine hair. Each half of the mary glands of sows.
udder of the ewe is craniomedial to the The caudal mammary glands of the sow
inguinal sinus (a pouch of skin lined receive blood from the caudal superficial
with scent glands) of the same side. epigastric arteries and to some extent from
Supernumerary teats in the ewe do not the caudal (deep) epigastric arteries. The
appear to have separate gland tissue, as is cranial pairs receive blood from the
frequently found in the cow. The sphincter branches of the cranial (deep) epigastric
muscle around the papillary duct is poorly arteries. Cranial and caudal epigastric
developed, so closure is affected by elastic arteries anastomose dorsal to the abdomi-
tissue in the end of the teat. nal mammary glands.
The lymphatic vessels from all but the
cranial one or two glands on each side
Mammary Glands of Swine drain to the ipsilateral superficial inguinal
lymph nodes. The lymphatic vessels from
The normal number of teats in the domes- the cranial few glands may drain to the
tic hog is seven pairs, or 14 teats, with the sternal lymph nodes, the superficial cervi-
first pair just caudal to the junction of the cal lymph nodes, or both.
sternum and costal arch and the last pair in The teat of the sow contains two streak
the inguinal region (Fig. 29‐6). The number canals and two teat cisterns. Each teat

(A) (B)

Figure 29-6. (A) Caudal view of lactating dairy goat. The caprine mammary udder has two glands with
two teats. (B) Lateral view of lactating sow. The typical sow has seven pairs of glands.